U.S. Uncovers Russian Plot to Assassinate C.E.O. of German Arms Maker

American intelligence agencies uncovered a Russian plot to kill the chief executive of a German weapons manufacturer, according to multiple Western officials, as Moscow steps up a campaign to undermine support for Ukraine’s war effort.

The United States warned Germany about the plot, and German officials increased protection for Armin Papperger, who leads Rheinmetall, which makes artillery shells and tanks that Ukraine has used in its war against Russia.

This year, Russian military intelligence has carried out a series of arsons aimed at disrupting the supply of weapons and other materiel to Ukraine, prompting the expulsion of undercover spies and warnings from NATO. The assassination plot is a significant escalation, officials said, representing a more concerted covert effort to deter Western companies from producing supplies for Ukraine.

A senior Western intelligence official said that the threats were flagged this past spring. Mr. Papperger was the only defense industry figure who was targeted by name or for whom the Russians appeared to have developed an advanced plan for the assassination, officials said. The officials spoke on the condition of anonymity to discuss the Russian operation.

The senior Western intelligence official said the plan was advanced to the point where Mr. Papperger had taken protective measures. Other threats that targeted European defense industry officials were more vague, the official said.

The plot, and the U.S. efforts to disrupt it, were earlier reported by CNN.

American, German and NATO officials would not comment on specifics of the plot, but they denounced Moscow’s sabotage and hybrid-style attacks in Europe.